Search Blog

Share this:

November 18, 2015

Meet the Researcher with Dr. Michael Yaszemski

By Center for Regenerative Medicine

Michael Yaszemski, M.D., Ph.D., physician, orthopedic surgeon and engineer, wants to make it clear that the advances in orthopedic regenerative medicine are the product of teamwork. During his recent talk entitled "Mayo’s History of Military Research and Musculoskeletal Regenerative Medicine of Today," Dr. Yaszemski discussed the recent developments in regenerative orthopedic surgery and took the time to fully credit his team members for the hard work they've done.

Since the advent of modern medicine there have been four eras of orthopedic surgery: resection, fusion, replacement and, now, regeneration. Resection was the process used in the very early days of surgery in which damaged joints were removed completely. This alleviated any pain but left patients unstable and unable to move freely. Next came fusion in which an injured joint was removed and the two bones fused together. Fusion gave patients stability but at the cost of mobility. In the 1950s replacement became the primary method thanks to the work done at Mayo Clinic under the guidance of Mark B. Coventry, M.D. During this era an injured joint was replaced with a metal or synthetic joint, which largely restored a patient's mobility. The issue with replacement is that the artificial joints will ultimately deteriorate, requiring repeat surgeries.

Today, in the era of regeneration, doctors wish to give patients the ability to regrow their own musculoskeletal cells, restoring mobility and stability, all without the need for repeat operations. Dr. Yaszemski explained several of the structures involved.

Bone regeneration is the regrowth of the bones themselves. This is done by first creating scaffolding for the bone to use while it grows inside the body. Each scaffold can be made from a variety of substances ranging from silk and collagen to polyester and titanium. These scaffolds can be implanted either surgically as one large piece or via injection in which the scaffold is introduced as a liquid that then hardens into a solid shape. Once the scaffold is in place cells can then be introduced which will then grow the new bone.

Tendon injuries are commonly in the operating room and the current treatment method leaves something to be desired, relying largely on sewing the two pieces together and hoping that they heal. Challenges are present in the regrowth of tendons as they require an entirely different construction and must endure a dramatic amount of force but Dr. Yaszemski's lab has produced a scaffold in which collagen can grow in conjunction with bone.

The breakdown of cartilage causes several conditions including: cartilage degenerative joint disease, post-traumatic cartilage regeneration, and osteochondritis dissecans, all of which can be treated. However, while those treatments can be effective, they will not last. Much like receiving an artificial hip, a patient who has undergone cartilage surgery will ultimately need a repeat operation. Regenerative medicine offers a new option for the treatment of cartilage repair in which an injection of growth factors and cell scaffolding can regrow a patient's own cartilage, repairing it indefinitely.

Nerves are the final structure that Dr. Yaszemski covers in his talk. Currently, if patients suffer from nerve damage they have no option other than to live with limited or no sensation to a part of their body. However, his lab is working to create scaffolds that allow nerve regrowth. Such scaffolds, which look something like long winding tubes, have already been implemented in animal models and have shown nerve growth spanning gaps in the animal's spine.

With these advancements the options for patients are expanding and there may soon be a day where orthopedic surgery can completely repair their injuries as if they had never happened.